Refrigerator having multiple temperature cooling elements



Q June 3, 1952 G. A. GRUBB ET AL 2,598,737

REFRIGERATOR HAVING MULTIPLE TEMPERATURE COOLING ELEMENTS Filed Feb. 26,1948 5 Sheets-Sheet 1 I j /f /J June 3, 1952 G. A. GRUBB ET AL 2,598,737

REFRIGERATOR HAVING MULTIPLE TEMPERATURE COOLING ELEMENTS Filed Feb. 26,1948 5 Sheets-Sheet 2 June 3, 1952 v G. A. GRUBB ET AL 2,598,737

REFRIGERATOR HAVING MULTIPLE TEMPERATURE COOLING ELEMENTS Filed Feb. 26,1948 5 Shets-Sheet 5 [W MW J n 3, 1952 G. A. GRUBB ETAL 5 Sheets-Sheet 47 w I 3 T 1 J J w a x W m z f w Z 3 9 2 f 4 4 f Filed Feb. 26. 1948 June3 1952 a. A. GRUBB ET AL 3,

REFRIGERATOR HAVING MULTIPLE TEMPERATURE COOLING ELEMENTS Filed Feb. 26,1948 v 5 Sheets-Sheet 5 M MW y h @w:

Patented June 3, 1952 REFRIGERATOR HAVING MULTIPLE TEM- PERATURE COOLINGELEMENTS Gunnar Axel Grubb, Stockholm, and Per Arne Backteman, Lulea,Sweden, assignors to Aktiebolaget Elektrolux, Stockholm, Sweden, acorporation of Sweden Application February 26, 1948, Serial No. 11,188In Sweden February 28, 1947 14 Claims. (Cl. 62-1195) This inventionrelates to refrigeration, and is concerned with cooling separatecompartments of a household refrigerator with the aid of coolingelements operable at different temperatures. More particularly, theinvention is concerned with cooling subdivided compartments of arefrigerator with the aid of absorption refrigeration apparatus of theinert gas type having a low temperature cooling element and a highertemperature cooling element.

It is an object of the invention to provide an improvement for coolingseparate compartments of a household refrigerator by cooling elementsoperable at different temperatures, particularly to efiect cooling ofeach compartment by a cooling element having a refrigerant passage whichis disposed essentially in a single vertical plane. This may beaccomplished by providing cooling elements formed of looped coils, eachlooped coil having straight portions and connecting bends disposedessentially in a single vertical plane, and positioning such loopedcoils operable at different temperatures alongside one another inseparate compartments at opposite sides of a vertical partition, or oneabove the other in the same vertical plane at opposite sides of ahorizontal partition.

Another object of the invention is to provide an improved householdrefrigerator, having a number of compartments which are cooled bycooling elements of an absorption refrigeration system of the inert gastype, wherein one compartment serving as a freezing section is cooled bya vertically disposed cooling element which extends for a major distanceof the height of such freezing section. This is accomplished byproviding a low temperature cooling element for the freezing sectionwhich comprises a looped coil having straight portions and connectingbends in a single vertical plane, and desirably includes a vertical wallmember in good thermal relation with the looped coil which provides arelatively extensive heat transfer surface, and also horizontal platesheat conductively connected to the coil straight portions for supportingice trays and other matter to be frozen. The wall member of the coolingelement may serve as a side wall of the freezing section and promotesmaintaining a substantially constant temperature throughout all regions,thereby avoiding a steep vertical temperature gradient in the freezingsection.

The above and other objects of the invention will be more fullyunderstood upon reference to the following description and accompanyingdrawings forming a part of this specification, and of which:

Fig. 1 more or less diagrammatically illustrates an absorptionrefrigeration system of the inert gas type embodying the invention;

Fig. 2 is a top plan view of the coolin unit of Fig. l to illustrate theconnectiOns to the upper part thereof more clearly;

Fig. 3 is a fragmentary view of'the refrigeration system shown in Fig. lto illustrate details more clearly;

Fig. 4 is a View similar to Fig. 1 illustrating another embodiment ofthe invention;

Fig. 5 is a top plan view of the cooling unit of Fig. 4 to illustratethe connections to the upper and lower ends thereof more clearly;

Fig. 6 is a view of the cooling unit taken at line 6--6 of Fig. 4;

Fig. 7 is a View similar to Figs. 1 and 4 illustrating a furtherembodiment of th invention;

Fig. 8 is a side vertical sectional view of a refrigerator and parts ofa refrigeration system associated therewith which is generally like thatshown in Fig. l; v

Fig. 9 is a front elevation of the refrigerator illustrated in Fig. 8,the front door or closure member therefor being omitted;

Fig. 10 is a side vertical sectional view of a refrigerator and parts ofa refrigeration system associated therewith which is generally like thatshown in Fig. 4

Fig. 11 is a front elevation of the refrigerator illustrated in Fig. 10,the front door or closure member therefor being omitted;

Fig. 12 is a side vertical sectional view of a refrigerator and parts ofa refrigeration system generally like that shown in Fig. 7; and

Fig. 13 is a front elevation of the refrigerator illustrated in Fig. 12,the front door or closure member therefor being omitted.

Referring to Fig. 1, the invention i embodied in an absorptionrefrigeration system of a uniform pressure type in which an inert gas orauxiliary pressure equalizing fluid is em loyed. In a system of thistype a refrigerant fluid, such as liquid ammonia, for example, isintroduced into an evaporator structure or cooling unit M from acondenser I5 in a manner which will be explained presently. Therefrigerant fluid evaporates and diffuses in cooling unit l4 into aninert gas, such as hydrogen, for example, to produce a refrigeratingeffect.

The resulting gas mixture of refrigerant and inert gas flows from thecooling unit I4 through an outer passage l6 of a gas heat exchanger I1and vertical conduit l8 into an absorber comprising a vessel I9 and alooped coil 20, 'In the absorber vessel I9 and coil 20 refrigerant vaporis absorbed by a suitable absorbent, such as water,

. a conduit 23.

From the vessel l9 enriched absorption liquid flows through a conduit 24and an inner passage 25 of a liquid heat exchanger 26 into the lower endof a vapor liquid lift tube 2'! of a generator unit 28. The generator orvapor expulsion unit 28 comprises a heating tube 29 having the vaporlift tube 21 and a boiler pipe 30 in heat conducting relation therewith,as by welding, for

example. By heating generator unit 28, as by an electrical heatingelement or a gaseous or liquid fuel burner (not shown), liquid is raisedby vapor lift action through tube 21 into the upper part of boiler pipe30. The liberated refrigerant vapor entering boiler pipe 30 through tube21,

together with vapor expelled from solution in the pipe 30, flowsupwardly into an air-cooled rectifier 3| and thence into the condenser lwhich may be air-cooled and provided with heat dissipating members (notshown). Refrigerant vapor is liquefied in the condenser l5 and returnsto the cooling unit M to complete the refrigerating cycle, as will beexplained presently. The weakened absorption liquid, from whichrefrigerant vapor has been expelled, is conducted from boiler pipe 30through aconduit 32, outer passage 33 of liquid heat exchanger 26 andconduit 2| into the upper part of the absorber coil 23,.

In accordance with this inventionthe'cooling unit M comprises twovertically disposed cooling elements Ma and Mb which are operable atdifferent temperatures and adapted to be positioned in a thermallyinsulated interior of a refrigerator cabinet for cooling severalcompartments therein. In the embodiment of Figs. 1 and 2-, thevertically extending cooling elements Ma and Mb are in the form oflooped coils positioned alongside one another and each of. which isdisposed in a single substantially vertical plane.

The cooling elements Ma and Mb are connected to one anotherand to thegas heat exchanger I! in such manner that inert gas weak in refrigerantflows from the upper end of ab- Liquid refrigerant is supplied fromcondenser l5 to the upper ends of cooling elements Ma and Mb throughconduits 36 and 31, respectively. Hence, liquid refrigerant flowsdownwardly in cooling element Ma in parallel flow with inert gas anddownwardly in cooling ele-, ment Mb in counterfiow to inert gas passingupwardly therethrough. Refrigerantvapor from theigenerator unit 28 flowssuccessively through condenser sections I511, b and [5a, and refrigerantvapor liquefied in condenser section l5b.

flows therefrom through conduit 36 to the upper end of cooling elementMa. Refrigerant vapor which is not liquefied in condenser section [5b.then passes into condenser section 150 and condens s therein. and suchcondensate .flows'therefrom through conduit 31 to the upper end ofcooling element Mb.

In order to insure liquid refrigerant being supplied .to the upper endof cooling element Mb when air cooling of condenser I5 is employed andthe temperature of the air is relatively low, under which conditionsthere is a tendency for a greater part of the refrigerant vapor to beliquefied in condenser sections l5a and l5b, a

conduit 38 is provided to divert liquid refrigerant from condensersection 15a into condenser section I50, such conduit including a trap sothat a liquid seal will form therein. In this way a supply of liquidrefrigerant to cooling element Mb from condenser section I50 is insuredwhen the quantity of refrigerant vapor liquefying in thatcondensersection is substantially reduced due to" low temperature air cooling ofthe condenser [5.

Any unevaporated refrigerant passes from the lower ends of coolingelements Ma and Mb into one leg of a U-shaped conduit 39 whose oppositeleg is connected to the absorber vessel H) at a .region which is belowthe normal liquid level therein. In order to insure draining ofunevaporated liquid from the cooling unit M, the conduit 39 is desirablyconnected to the lowest point thereof which may be 'at either of thecooling e1e ments Ma or Mb or the cross connection 34 therebetween.

Since the inert gas flows successively through thecooling elements Maand Mb, the gas in'the cooling element Ma contains a lesser amount ofrefrigerant vapor than in the cooling element Mb. The partial vaporpressure of the refrigerant is a gradient, so that the temperature ofliquid refrigerant in the cooling elements is also a gradient, theevaporating temperature of liquid being lower in the cooling element Mawhich constitutes the freezingsection of the cooling unit. In order toreduce and lower the mean or average, temperature of cooling elementMap, the conduit 36 through which liquid refrigerant is supplied to thatcooling'element is arranged in thermal exchange relation with the upperpart of cooling element Mb, as best seen in 2. With this arrangement therelatively cool gas mixture of refrigerant vapor and inert gas, which isabout to pass from the upper end of cooling element Mb, is effectivelyutilizedto abstract heat from liquid refrigerant in conduit 35 prior toentering the low temperature cooling element Ma. r

In order to simplify Figs. 1 to 3, the cooling unit M has beenillustrated apart from a household refrigerator. One manner in which thecooling elements Ma and Mb of an absorption refrigeration system likethat just described may be positioned in a thermally insulatedinteriorof a household refrigerator cabinet for coolin separate compartmentstherein is diagrammatically illustrated in Figs. 8 and 9. In Figs. 8 and9 the cooling unit M is disposed in a cabinet 40 having a space 4|defined by an inner liner or shell 42 which is arranged to be supportedwithin an outer metal shell '43 and insulated therefrom with anysuitable insulatin material 44. The space H is provided with a frontaccess opening 45 which is adapted to be closedby, an insulated door orclosure member (not shown) hinged to the front of the cabinet 40.

In order to position the cooling unit M in the space 4|, the rear wall46/ of the cabinet 40. .is

having poor heat conducting properties. A cover or closure member 49 forthe opening, which contains insulating material 50 and through which thegas heat exchanger- I1 and conduits 36, 31 and 39 extend,is arranged tobear against gaskets 5I and 52'of suitable insulating material andremovably secured in any suitable manner (not shown) to the rear wall46. The cabinet 40 is provided with a vertically extending compartment53 at the rearthereof in which the generator unit 28, condenser I5,absorber vessel I9 and coil 20, and conduits connecting these parts arehoused in a well known manner.

In accord with the invention, the low and higher temperature coolingelements Ma and I4!) are located at opposite sides of a vertical wallmember 54 in the space 4| which subdivides the latter into compartments55 and 56. The wall member 54 may be formed of suitable insulatingmaterial or spaced apart metallic plates having insulation therebetweenand serves as a thermally insulated partition between the compartments55 and 56.

The cooling or refrigerating effect produced by the low temperaturecooling element I4a is utilized to effect cooling of the compartment 56which may be referred to as a freezing section adapted to receive icetrays 51, frozen food packages and other matter to be frozen. In orderto support ice trays in good thermal contact with the straight portionsof the looped coil forming cooling element I4a, plates 56 or otherstructure may be arranged in heat conducting relation with such straightportions to provide suitable tray supporting surfaces. Such plates 58may be heat conductively connected to a vertical wall member 58a whichserves as a side wall of the compartment 56. The access opening of thefreezing compartment 56 at the forward part thereof may be provided witha hinged door (not shown) desirably formed of transparent material whichmay be spring biased to its closed position in any suitable manner andreadily opened by grasping a part thereof.

The cooling effect produced by the higher temperature cooling element I4b is utilized to cool air in the compartment 55 and abstract heat fromfood products which may be stored therein on suitable shelving indicatedin dotted lines at 59 in Fig. 9. The vertically disposed looped coilforming the higher temperature cooling element I4b desirably is providedwith a housing 60 fabricated of material having good heat conductingproperties to promote effective cooling of the compartment 55, and thecooling element I4b may be in good thermal contact with the side wall ofthe housing 60 directly opposite a side wall of the inner shell 42.

By providing vertically disposed cooling elements Ma and M1) whichoccupy a major portion of the heightof the compartments 55 and 56 andextend downwardly from regions closely adjacent to the top wallsthereof, efficient cooling of the compartments is effected and coolingtemperatures are produced therein which are more or less uniform in allparts thereof. This'is especially important in the freezing compartment56 in which a steep vertical temperature gradient is undesirable,because all parts thereof should be made available for storing frozenfood packages and the like at a sufiiciently low freezing temperaturewithout any danger of thawing taking place.

A further advantage of the vertical disposition of cooling elements Maand MI) in single vertical planes closely'adjacent to one another isthat an opening 41 of minimum size is required at the rear wall 46 forinserting thecooling unit I4 into the storagespace 4|. In this .way thetendency for heat transfer intothe compartments 55 and 56, about theclosure member 49 which closes the opening, is materially reduced andefiicient cooling by the cooling elements Ma and MD is promoted. Thehousing 60 for the higher temperature cooling element I4b may beremovably secured thereto after the cooling unit I4 is located in thespace 4|, and to this end suitable clamping means may be provided at theinterior of the housing to establish a good heat conducting connectionbetween the higher temperature coil and side wall of the housing,thereby providing a relatively extensive heat transfer surface forcooling air in the compartment 55..

In Figs. 4 to 6 another embodiment of the invention is illustrated whichdiffers from the embodiment just described in that the lowest point ofthe cooling unit is substantially at the same level or immediately abovethe highest point of the absorber. In Figs. 4 to 6 parts similar tothose shown in Figs. 1 to 3 are referred to by the same numeralsincreased by one hundred. 'As in the first described embodiment, thecooling elements H4a and H41) in Figs. 4 to 6 are in the form of loopedcoils positioned alongside one another, each coil being disposed in asingle substantially vertical plane.

The cooling elements H4a and II4b are connected to one another and tothe gas heat exchanger in such manner that inert gas weak in refrigerantflows from the absorber coil I20 through the inner passage I22 of thegas heat exchanger I I1 into the lower end of the low temperaturecooling element I No. After flowing upwardly through cooling elementH4a, inert gas passes through a conduit I34 connecting the upper ends ofthe cooling elements and then flows downwardly through the highertemperature cooling element I I4b. From the lower end of cooling elementH4b inert gas enriched in refrigerant passes through a conduit I35 intothe outer passage H6 of the gas heat exchanger, as best seen in Fig. 5.

Liquid refrigerant is supplied from condenser H5 to the upper ends ofcooling elements H411 and I I 4b in the same manner that refrigerant isdelivered from condenser I5 to cooling elements Ma and I4b in theembodiment first described. Accordingly, liquid refrigerant is deliveredthrough conduit I36 to the upper end of low temperature cooling elementHM, and refrigerant is conducted through conduit I31 to the upper end ofhigher temperature cooling element H4b. The refrigeration system beingdescribed differs from the embodiment first described in that liquidrefrigerant flows downwardly in cooling element H401. in counterflow toinert gas and downwardly in cooling element I I4b in parallel flow withinert gas. Any unevaporated refrigerant. which flows from the lower endsof cooling elements H411 and H42) passes into the outer passage I I6 ofthe gas heat exchanger and drains by gravity back to the absorber vesselH9.

In order to effect precooling of liquid refrigerant supplied throughconduit I36 to the cooling element H4a, this conduit is arranged in heatexchange relation with the upper part of cooling element H4b, as shownin Figs. 5 and 6. A dam or barrier I6I is provided in the conduit I34,as shown in Fig. 4, so that liquid refrigerant suplooped coils.

I plied to each cooling element will not be diverted ;.into the othercooling element. Since the inert .gas flows successively through thecooling elements ma; and H412 and the gas in cooling element I I4acontains a lesser amount of refrigerant vapor than in cooling element42), the cooling element 4:; will operate at a lower temperature thancoolingelement H412 and constitutes the freezing section of thecoolingunit II4.

One manner in which the cooling elements I Ma and I I41) of anabsorption refrigeration system like that just described may bepositioned in a thermally insulated interior of a household refrigeratorcabinetfor cooling separate compartments therein is diagrammaticallyillustrated in Figs. 10 and 11. In Figs. 10'and 11 parts correspondingto'those shown in Figs. 8 and 9 are designated by the same referencenumerals increased by one hundred. In Figs. 10 and 11 the space MI isdivided into compartments I55 and I56 by a vertical partition I54 whichextends downwardly from the top of the space and a horizontal partitionI62 which extends from a side wall of the inner shell I42 and is joinedto 7 The low temperaturecooling element M is located at one side of thevertical partition I54 in the compartment I56, and the refrigeratingeifect produced by this cooling element is utilized I to coolcompartment I56 which is employed as a freezing section. As describedabove in connection with Figs. 8 and 9, the compartment I56 may beprovided with a hinged closure member (not shown) to gain access thereinand keep the freezing section closed to maintain a low temperaturetherein. 1 r v The'higher temperature cooling element H4!) is located atthe opposite side of the vertical partition I54 in the compartment I55,and the refrigerating efiect produced by this cooling'element isutilized to cool air and abstract heat from food products which may bedisposed on shelving indicated in dotted lines at I59 in Fig. 11. As inthe previously described embodiment, the cooling element I I4b= may beconcealed ina shell or housing I66 and desirably in heat conductingrelation therewith. 7

By locating the cooling elements I Ma and I Hi) closely adjacent to eachother-at oppositesides of the vertical insulated partition I54,a compactcooling unit isprovided which occupies a minimum amount of-space andrequires an opening at the rear wall [46' which is relatively small forinserting the cooling unit into the interior of the refrigerator cabinetI46. y

In Fig.7 a-furtherl.embodiment of theinvention isillustrated."in-v'vhich the. low and higher temperature cooling elementsare disposed in the same-vertical plane onefahove the other for coolingseparate compartments. in a thermally insulated interior of arefrigerator cahinet.-- m Fig. '1 parts correspondinggtoptliose in thefirst described embodiment are referred to by the" same referencenumerals increasedfby two hundred. In Fig. 7 the cooling elements2I4a-a'nd 2I'4b'are in the form of looped coilspositioned'gone above theotherin the. same vertical plane, anda gas heat exchanger 2'63;is i

' e cooling elements 2H}; andi2 l4b are the nected in the gas-circuit in' such manner that inert gas weak in refrigerant fio'wsfromthe upper.

end of the absorber co'il 220 through a conduit nterposed between the '264, outer passage 2I6 of gas heat exchanger H1 and conduit 223 into theouter passage 265 'of the gas heat exchanger 263. From the gas heatexchanger passage 265 inert gas flows upwardly through low temperaturecooling element 2I4a and leaves the latter through a conduit 266. Theconduit 266 is in the form of a looped coil which is in the samevertical plane as the cooling elements 2 Ma and 2 I41) and a portionthereof serves as the inner passage of the gas heat exchanger 263. Thelower end of conduit 266 communicates with the upper end of the coolingelement 2 I41), and, after inert gas passes downwardly through suchcooling element, inert gas rich in refrigerant flows through the innerpassage 222 of gas heat exchanger 2I1 to the absorber vessel 2I9.

-Liquid'refrigerant formed in-the condenser 2 I 5 flows therefromthrough a conduit 261 to the upper end of the cooling element 2 I411;the conduit- 261 being formed'to provide a trap 268 which is filled withliquid. Liquid refrigerant flows downwardly through cooling element 2I4ain counterflow to inert gas and is diverted by a dam or barrier 269 atthe lower end of this cooling element intothe upper end of a conduit216. From conduit 210 liquid refrigerant is introduced into the upperend of cooling element 2 I41) and flows downwardly through this coolingelement in parallel flow with inert gas. In order to drain any liquidwhich may collect in the outer passage 265 of gas heat exchanger 263, 'aU-shaped conduit 21I is provided having one leg connected to the lowestpart of I gas heatexchanger passage 265 and the other leg connected tothe upper part of cooling element 2I4b. Further, a conduit 212 isprovided for draining liquid from the outer passage 2 I 6- of gas heatexchanger 2I1 to the absorber vessel 219 at a region below the liquidlevel therein. 7

Since inert gas flows successively through cooling elements 2 Ma and 2I41? and the gas in cooling element 2I4a contains a lesser amount ofrefrigerant vapor than in cooling element -2I4b, the cooling element2I4a will operate at a low temperature and cooling element 2 I 41) at ahigher temperature. By providing the gas heat exchanger- 263, inert gasweak inrefrigerant and fiowing to the low temperature cooling element2I4a will be effectively precooled by cool gas passing fromthe lowtemperature cooling elemerit-2M4; to the higher temperature coolingelement 2I4b. In this way the mean or average temperature of coolingelement 2 Mr: is decreased and that of cooling element 2I'4b isincreased due to heat transfer from inert gas flowing-in the outerpassage 265 to the gas flowing in the inner passage or conduit 266 ofthe gas heat exchanger 263. i

One manner in which the cooling elements M411 and 2I4b of an absorptionrefrigeration system likerthat just describedmay be positioned in athermally insulated interior of a household refrigerator cabinet forcooling separate compartments' therein is; diagrammatically illustratedin -Figsq1f2 and 13; 'In Figs. 12 and 13 parts corresponding tothoseshown in Figs. 9 and 10' are designated by the same reference numeralsincreased by two hundred.

In Figs. 12 and 13- the space 241' is divided into" compartments 255and'2'56 by a horizontal partition-2.16 which may comprise a wall memberformed of suitable insulating material. The

cooling effect produced by the low temperature cooling element 2I4c isutilized to effect cooling of the chm-Daftmenl; 25B Whlll Serves its affezing section adapted to receive ice trays, frozen food packages andother matter to be frozen.

While ice trays 251 are diagrammatically illustrated as being supportedand in thermal contact with the straight portions of the upper loopedcoil 2 [4a, it is to be understood that plates or other suitablestructure may be provided for supporting a number of ice trays and othermatter, and that such structure may be fixed in good heat conductingcontact with the looped coil 2l4a after the cooling unit 2 is positionedin the space 2 through the opening 241 in the rear wall 246 of thecabinet 240. The cooling effect produced by the higher temperaturecooling element 2l4b is employed to cool air in the lower compartment255 and abstract heat from food products which may be disposed onshelving (not shown) disposed in this compartment.

As explained above in connection with the previously describedembodiments, the compartment 256 may be provided with a cover (notshown) hinged to the partition 213, for example, to gain access into thefreezing section and at other times keep it closed to maintain a lowtemperature therein. The insulating partition 213 may be formed ofseparate sections which interlock in any suitable manner, as indicatedat 214 in Fig. 13, the separate sections being shaped to fit snuglyabout parts of the gas-heat exchanger 263 connecting the upper and lowercooling elements HM and 2I4b.

In view of the foregoing it will now be understood that an improvedrefrigerator has been provided in which low and higher temperaturecooling elements are arranged to cool different compartments, suchcooling elements being formed of looped coils each of which is disposedessentially in a single vertical plane. In the embodiments of Figs. 8 to11 the cooling elements'are disposed at opposite sides of a verticalwall member, while in the embodiment of Figs. 12 and 13 the low andhigher temperature cooling elements are disposed one above the other atopposite sides of a horizontal wall member and located substantially inthe same vertical plane. With such disposition of the cooling elementsin the insulated interior of a household refrigerator cabinet, anopening of minimum size is required in a wall of the cabinet forpositioning the cooling elements therein when the latter form thecooling unit or evaporator structure of absorption refrigerationapparatus employing an inert gas as a pressure equalizing agent.

By cooling the freezing section of a household refrigerator with the aidof a low temperature I cooling element comprising a looped coil disposedessentially in a single vertical plane a steep vertical temperaturegradient is avoided. Moreover, by arranging a vertical plate 58a in goodheat conducting relation with the looped coil, as seen in Fig. 9, foodpackages can be rapidly frozen on the plates 58 and thereafter stored inthe compartment 56 alongside the plate 58a for substantially the entiredepth of the compartment without any danger of thawing in any partthereof. Hence, by employing a vertically extending looped coil whichextends upwardly to regions above the bottom of the freezing section fora major portion of the height of this section, an arrangement isprovided for effectively storing frozen food packages and other matterto be frozen.

Whi1e several embodiments of the invention have been shown anddescribed, it will be apparent to those skilled in the art that variousmodifications and changes may be made without 10 departing from thespirit and scope of the invention, as pointed out in the followingclaims.

What is claimed is:

1. In a refrigerator comprising a cabinet defining an interior andpartitioning therein providing separate compartments, an absorptionrefrigeration system having a circuit for inert gas including coolingelements which always are in open communication with one another andoperable at different average temperatures, at least one of said coolingelements being operable at a lowtemperature for freezing matter andarranged to effect cooling of one compartment at one side of saidpartitioning adapted to serve as a freezing section, said one coolingelement including means providing a vertically extending refrigerantpassage which is substantially greater in length than the verticalextent thereof and occupies a major portion of the height of saidfreezing section, and another of said cooling elements being arranged atanother side of said partitioning to effect cooling of a differentcompartment.

2. An absorption refrigeration system having a circuit for inert gasincluding an absorber and cooling structure comprising a low temperaturecooling element and a higher temperature cooling element, a circuit forabsorption liquid including said absorber and a generator, each of saidcooling elements comprising means providing an elongated refrigerantpassage which is disposed essentially in a single vertical plane, saidcooling structure being so connected and arranged in said gas circuitthat inert gas enters and leaves at regions removed from the extremelower part thereof which extends downwardly to a level between the upperpart of said absorber and the liquid level therein.

3. An absorption refrigeration system having a circuit for inert gasincluding a plurality of gas heat exchangers, an absorber and low andhigher temperature cooling elements, each of said cooling elementscomprising means providing an elongated refrigerant passage which isdisposed essentially in a single vertical plane, one of said gas heatexchangers having a first passage connected to receive inert gas fromsaid absorber and a second passage connected to receive gas from saidhigher temperature cooling element and conduct such gas to saidabsorber, another of said gas heat exchangers having a first passageconnected to receive gas from the first passage of said one gas heatexchanger and conduct such gas to said low temperature cooling elementand a second passage connected to receive gas from said low temperaturecooling element and deliver such gas to said higher temperature coolingelement, said other gas heat exchanger being disposed between andsubstantially in the same vertical plane as said low and highertemperature cooling elements.

l. A refrigerator comprising a cabinet having the interior thereofsubdivided into compartments by partition means including a verticalinsulating wall, absorption refrigeration apparatus having a gas circuitincluding a low temperature cooling element and a higher temperaturecooling element, said low temperature cooling element being disposed inone of said compartments and comprising a looped coil having straighthorizontally extending portions and connecting bends disposedessentially in a single vertical plane, structure in good thermalrelation with said coil providing a vertical wall having a relativelyextensive heat transfer surface which extends a major portion of thedistance from the bottomto the topof saidone compartment. K

5. An absorption refrigeration system having a circuit. foriinert gasincluding: a. low temperature cooling. element. and a highertemperature, cool.- ing element, each of said cooling elementscomprising means providing an elongated passage. for refrigerantwhich isdisposed essentially in a single. vertical. plane, 'means to supplyrefrigerant fiuidtoeach of said cooling elements for down.-

wardxflow therethrough, said cooling elements being so" connectedin'said' gas circuit that gas flows in parallelwith refrigerant in oneof said cooling. elements and counter-current to refrigerantin anotherof said cooling elements.

absorption refrigeration system as set forth-in claim in which'inert gasfiowsupwardly in said low temperature cooling element: and downwardly.in said higher temperature cooling element. 7. An absorptionrefrigeration system having a circuit for inert gas including anevaporator in which refrigerant evaporates in the presence of an inertgas and an absorber, a circuit for absorption liquid including saidabsorber and a generator, said, evaporator being so connected andarrangedin said gas circuit that inert gas enters'and leaves regionsremoved from. the 'extreme' lower part thereof, and means including aconnection for draining liquid from the extreme lower part of, saidevaporator to said absorption liquid circuit, said connectionp-roviding'a path of flow for liquid through which inert. gas normallydoes not pass and which communicates with'the absorption liquid circuitat a region below theliquid surface level thereof.

'8. An absorption refrigeration system having a circuit for inert gasincluding, an evaporator in which refrigerant evaporates in the presenceof an inert gas and an absorber comprising a looped coil'an'd a vessel.adapted to hold a body of liquidabsorbent, a circuit for liquidabsorbent including said absorber and a generator, said evaporator beingvertically disposed and so connected and arranged in said gas circuitthat inert 'gas' enters and leaves regions removed from the extremelower part thereof which is located at a level between the upper part ofsaid looped coil and the liquid surface level in said vessel, and meansincluding a, connection for draining liquid from: the extreme lower partof said evaporator to said absorption solution circuit, said connectionproviding a path of flow for liquid through which'inert gas normallydoes not pass and which communicates with the absorption liquid circuitat a'region below the liquid surface level thereof. '9..An absorptionrefrigeration system having a circ uit for inert gas including aplurality of gas heat exchangers, an absorber and low and highertemperature cooling elements, each of said cooling elements comprisingmeans providing an elongated refrigerant passage which is disposedessentially in a single vertical plane, one of said gas heat'exchangershaving a first passage connected to receive inert gas from said absorberand a second passage connected to receive gas from'said highertemperature cooling element and conduct such gas'to said absorber, andanother of said gas heat exchangers having a first passage connected toreceive gas from the first passage of said one gas heat exchanger andconduct such gas to said low temperature cooling element and a secondpassage connected to receive gas from said low temperature coolingelementand deliver such gas to saidhigher temperaturecoolf ingelement,one of said cooling elements having at least a part thereof at a levelbetween the upper part of said absorber and the liquid level therein.

10. A refrigerator comprising a cabinet having the interior thereofsubdivided into compartments by partition means including an insulatingwall, absorption refrigeration apparatus having a gas circuit includinga low temperature cooling element and a higher temperature cooling.element, said higher. temperature cooling element being arranged toeffect cooling of one of said compartments, said low temperature coolingelement being disposed in another of said compart- 'ments and comprisinga looped coil having straight horizontally extending portions andconnecting bends disposed essentially in a single vertical plane, andsaid looped coil extending a major portion of the distance from thebottom to the top of said other-compartment.

11. In a refrigerator comprising a cabinet having the interior thereofsubdivided into compartments by partition means, an absorptionrefrigeration system including a low temperature cooling element and ahigher temperature cooling element disposed at opposite sides of saidpartition means and arranged to effect cooling of differentcompartments, and each of said cooling elements comprising means formingan elongated path of flow for circulation of liquid refrigerant andinert gas therethrough to provide a relatively extensive gas and liquidcontact surface between the aforementioned fluids, the elongated path offlow of each of said cooling elements being disposed in a singlevertical plane.

12; In a refrigerator comprising a cabinet having the interior thereofsubdivided into compartments by partition means including a verticalwall, an absorption refrigeration system including a low temperaturecooling element and a higher temperature cooling element which aredisposed relativelyclose to and alongside one another at opposite sidesof said vertical wall and arranged to effect cooling ofIdifferentcompartments, and each of said cooling elements comprisingmeans forming an elongated path of flow for circulation of liquidrefrigerant and inert gas therethrough to provide a relatively extensivegas 7 and liquid contact surface between the aforementioned fluids, theelongated path of flow of each of said cooling elementsbeing disposed ina single vertical plane.

13. Apparatus as set. forth in claim 11 in which said partition meansincludes a horizontal wall and said cooling elements are disposed atopposite sides of said wall and substantially in the same vertical planefor cooling different compartments. V

14. In a refrigerator comprising a cabinet having thermally insulatedwalls forming a space divided into several compartments by partitionmeans, a refrigeration system comprising a condenser in whichrefrigerant vapor is liquefied and cooling structure, said coolingstructure including a low temperature cooling element and a highertemperature cooling element which always are in open communication withone another and operable at substantially the same pressure, said lowand higherv temperature cooling elements being arranged in the spacetoeffect coolingrof separate compartments therein, each of said coolingelements including refrigerant passage forming means which is disposedessentially in asingle vertical plane, and conduit means connected tosaid condenser andto the upper parts of both of said coolingelementsatregions removed from 13 the lower ends thereof for initiallyintroducing liquid refrigerant into both of said cooling elements at theuppermost cold producing regions thereof.

GUNNAR AXEL GRUBB. PER ARNE BACKTEMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date Davenport Sept. 11, 1928 Number Re.17,078

Number Kogel Oct. 24, 1944

